For improving the contrast of a liquid-crystal display device, various investigations have been made for reducing the transmitted light in the front direction (that is, in the normal direction to the display panel) at the time of black level of display. In a liquid-crystal color display device, a color filter layer is disposed for each pixel in the cell, and a polarized light is introduced into the color filter layer for displaying a color image. However, the color filter layer has a depolarization effect, and it is known that the light that has been depolarized in the color filter layer scatters thereby causing one reason of increasing the transmitted light at the time of black level of display. As a means for solving the problem of transmitted light increase at the time of black level of display, as caused by the depolarization in the color filter layer, there is known a technique of arranging a polarizing layer between the color filter layer and the liquid-crystal layer in the cell (Patent Reference 1).
On the other hand, various proposals have been made also for improving the oblique-direction contrast in VA-mode liquid-crystal display devices and IPS-mode liquid-crystal display devices; however, all these are to propose arrangement of an optical film having predetermined optical characteristics outside the liquid-crystal cell (for example, Patent References 2 and 3).